glib/gtimer.c

   1 /* GLIB - Library of useful routines for C programming
   2  * Copyright (C) 1995-1997  Peter Mattis, Spencer Kimball and Josh MacDonald
   3  *
   4  * This library is free software; you can redistribute it and/or
   5  * modify it under the terms of the GNU Lesser General Public
   6  * License as published by the Free Software Foundation; either
   7  * version 2 of the License, or (at your option) any later version.
   8  *
   9  * This library is distributed in the hope that it will be useful,
  10  * but WITHOUT ANY WARRANTY; without even the implied warranty of
  11  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
  12  * Lesser General Public License for more details.
  13  *
  14  * You should have received a copy of the GNU Lesser General Public
  15  * License along with this library; if not, write to the
  16  * Free Software Foundation, Inc., 59 Temple Place - Suite 330,
  17  * Boston, MA 02111-1307, USA.
  18  */
  19
  20 /*
  21  * Modified by the GLib Team and others 1997-2000.  See the AUTHORS
  22  * file for a list of people on the GLib Team.  See the ChangeLog
  23  * files for a list of changes.  These files are distributed with
  24  * GLib at ftp://ftp.gtk.org/pub/gtk/.
  25  */
  26
  27 /*
  28  * MT safe
  29  */
  30
  31 #include "config.h"
  32 #include "galias.h"
  33 #include "glibconfig.h"
  34
  35 #ifdef HAVE_UNISTD_H
  36 #include <unistd.h>
  37 #endif /* HAVE_UNISTD_H */
  38
  39 #ifndef G_OS_WIN32
  40 #include <sys/time.h>
  41 #include <time.h>
  42 #include <errno.h>
  43 #endif /* G_OS_WIN32 */
  44
  45 #ifdef G_OS_WIN32
  46 #include <windows.h>
  47 #endif /* G_OS_WIN32 */
  48
  49 #include "glib.h"
  50
  51
  52 struct _GTimer
  53 {
  54 #ifdef G_OS_WIN32
  55   DWORD start;
  56   DWORD end;
  57 #else /* !G_OS_WIN32 */
  58   struct timeval start;
  59   struct timeval end;
  60 #endif /* !G_OS_WIN32 */
  61
  62   guint active : 1;
  63 };
  64
  65 #ifdef G_OS_WIN32
  66 #  define GETTIME(v) \
  67      v = GetTickCount ()
  68 #else /* !G_OS_WIN32 */
  69 #  define GETTIME(v) \
  70      gettimeofday (&v, NULL)
  71 #endif /* !G_OS_WIN32 */
  72
  73 GTimer*
  74 g_timer_new (void)
  75 {
  76   GTimer *timer;
  77
  78   timer = g_new (GTimer, 1);
  79   timer->active = TRUE;
  80
  81   GETTIME (timer->start);
  82
  83   return timer;
  84 }
  85
  86 void
  87 g_timer_destroy (GTimer *timer)
  88 {
  89   g_return_if_fail (timer != NULL);
  90
  91   g_free (timer);
  92 }
  93
  94 void
  95 g_timer_start (GTimer *timer)
  96 {
  97   g_return_if_fail (timer != NULL);
  98
  99   timer->active = TRUE;
 100
 101   GETTIME (timer->start);
 102 }
 103
 104 void
 105 g_timer_stop (GTimer *timer)
 106 {
 107   g_return_if_fail (timer != NULL);
 108
 109   timer->active = FALSE;
 110
 111   GETTIME(timer->end);
 112 }
 113
 114 void
 115 g_timer_reset (GTimer *timer)
 116 {
 117   g_return_if_fail (timer != NULL);
 118
 119   GETTIME (timer->start);
 120 }
 121
 122 void
 123 g_timer_continue (GTimer *timer)
 124 {
 125 #ifdef G_OS_WIN32
 126   DWORD elapsed;
 127 #else
 128   struct timeval elapsed;
 129 #endif /* G_OS_WIN32 */
 130
 131   g_return_if_fail (timer != NULL);
 132   g_return_if_fail (timer->active == FALSE);
 133
 134   /* Get elapsed time and reset timer start time
 135    *  to the current time minus the previously
 136    *  elapsed interval.
 137    */
 138
 139 #ifdef G_OS_WIN32
 140
 141   elapsed = timer->end - timer->start;
 142
 143   GETTIME (timer->start);
 144
 145   timer->start -= elapsed;
 146
 147 #else /* !G_OS_WIN32 */
 148
 149   if (timer->start.tv_usec > timer->end.tv_usec)
 150     {
 151       timer->end.tv_usec += G_USEC_PER_SEC;
 152       timer->end.tv_sec--;
 153     }
 154
 155   elapsed.tv_usec = timer->end.tv_usec - timer->start.tv_usec;
 156   elapsed.tv_sec = timer->end.tv_sec - timer->start.tv_sec;
 157
 158   GETTIME (timer->start);
 159
 160   if (timer->start.tv_usec < elapsed.tv_usec)
 161     {
 162       timer->start.tv_usec += G_USEC_PER_SEC;
 163       timer->start.tv_sec--;
 164     }
 165
 166   timer->start.tv_usec -= elapsed.tv_usec;
 167   timer->start.tv_sec -= elapsed.tv_sec;
 168
 169 #endif /* !G_OS_WIN32 */
 170
 171   timer->active = TRUE;
 172 }
 173
 174 gdouble
 175 g_timer_elapsed (GTimer *timer,
 176                  gulong *microseconds)
 177 {
 178   gdouble total;
 179 #ifndef G_OS_WIN32
 180   struct timeval elapsed;
 181 #endif /* G_OS_WIN32 */
 182
 183   g_return_val_if_fail (timer != NULL, 0);
 184
 185 #ifdef G_OS_WIN32
 186   if (timer->active)
 187     timer->end = GetTickCount ();
 188
 189   /* Check for wraparound, which happens every 49.7 days. */
 190   if (timer->end < timer->start)
 191     total = (UINT_MAX - (timer->start - timer->end - 1)) / 1000.0;
 192   else
 193     total = (timer->end - timer->start) / 1000.0;
 194
 195   if (microseconds)
 196     {
 197       if (timer->end < timer->start)
 198         *microseconds =
 199           ((UINT_MAX - (timer->start - timer->end - 1)) % 1000) * 1000;
 200       else
 201         *microseconds =
 202           ((timer->end - timer->start) % 1000) * 1000;
 203     }
 204 #else /* !G_OS_WIN32 */
 205   if (timer->active)
 206     gettimeofday (&timer->end, NULL);
 207
 208   if (timer->start.tv_usec > timer->end.tv_usec)
 209     {
 210       timer->end.tv_usec += G_USEC_PER_SEC;
 211       timer->end.tv_sec--;
 212     }
 213
 214   elapsed.tv_usec = timer->end.tv_usec - timer->start.tv_usec;
 215   elapsed.tv_sec = timer->end.tv_sec - timer->start.tv_sec;
 216
 217   total = elapsed.tv_sec + ((gdouble) elapsed.tv_usec / 1e6);
 218   if (total < 0)
 219     {
 220       total = 0;
 221
 222       if (microseconds)
 223         *microseconds = 0;
 224     }
 225   else if (microseconds)
 226     *microseconds = elapsed.tv_usec;
 227
 228 #endif /* !G_OS_WIN32 */
 229
 230   return total;
 231 }
 232
 233 void
 234 g_usleep (gulong microseconds)
 235 {
 236 #ifdef G_OS_WIN32
 237   Sleep (microseconds / 1000);
 238 #else /* !G_OS_WIN32 */
 239 # ifdef HAVE_NANOSLEEP
 240   struct timespec request, remaining;
 241   request.tv_sec = microseconds / G_USEC_PER_SEC;
 242   request.tv_nsec = 1000 * (microseconds % G_USEC_PER_SEC);
 243   while (nanosleep (&request, &remaining) == EINTR)
 244     request = remaining;
 245 # else /* !HAVE_NANOSLEEP */
 246   if (g_thread_supported ())
 247     {
 248       static GStaticMutex mutex = G_STATIC_MUTEX_INIT;
 249       static GCond* cond = NULL;
 250       GTimeVal end_time;
 251
 252       g_get_current_time (&end_time);
 253       if (microseconds > G_MAXLONG)
 254         {
 255           microseconds -= G_MAXLONG;
 256           g_time_val_add (&end_time, G_MAXLONG);
 257         }
 258       g_time_val_add (&end_time, microseconds);
 259
 260       g_static_mutex_lock (&mutex);
 261
 262       if (!cond)
 263         cond = g_cond_new ();
 264
 265       while (g_cond_timed_wait (cond, g_static_mutex_get_mutex (&mutex),
 266                                 &end_time))
 267         /* do nothing */;
 268
 269       g_static_mutex_unlock (&mutex);
 270     }
 271   else
 272     {
 273       struct timeval tv;
 274       tv.tv_sec = microseconds / G_USEC_PER_SEC;
 275       tv.tv_usec = microseconds % G_USEC_PER_SEC;
 276       select(0, NULL, NULL, NULL, &tv);
 277     }
 278 # endif /* !HAVE_NANOSLEEP */
 279 #endif /* !G_OS_WIN32 */
 280 }
 281
 282 /**
 283  * g_time_val_add:
 284  * @time_: a #GTimeVal
 285  * @microseconds: number of microseconds to add to @time
 286  *
 287  * Adds the given number of microseconds to @time_. @microseconds can
 288  * also be negative to decrease the value of @time_.
 289  **/
 290 void
 291 g_time_val_add (GTimeVal *time_, glong microseconds)
 292 {
 293   g_return_if_fail (time_->tv_usec >= 0 && time_->tv_usec < G_USEC_PER_SEC);
 294
 295   if (microseconds >= 0)
 296     {
 297       time_->tv_usec += microseconds % G_USEC_PER_SEC;
 298       time_->tv_sec += microseconds / G_USEC_PER_SEC;
 299       if (time_->tv_usec >= G_USEC_PER_SEC)
 300        {
 301          time_->tv_usec -= G_USEC_PER_SEC;
 302          time_->tv_sec++;
 303        }
 304     }
 305   else
 306     {
 307       microseconds *= -1;
 308       time_->tv_usec -= microseconds % G_USEC_PER_SEC;
 309       time_->tv_sec -= microseconds / G_USEC_PER_SEC;
 310       if (time_->tv_usec < 0)
 311        {
 312          time_->tv_usec += G_USEC_PER_SEC;
 313          time_->tv_sec--;
 314        }
 315     }
 316 }